The **scientific laws** they are propositions that state constant relationships between at least two factors. These propositions are expressed in formal language or even in mathematical language. For example: *Hubble’s law, Coulomb’s law, Ohm’s law.*

Scientific laws are always verifiable, that is, they can be verified.

- Scientific laws can refer to natural phenomena, and in that case they are called natural laws.
- However, they can also refer to social phenomena, in cases where they are formulated by social sciences. They are verifiable because they indicate characteristics common to many different social phenomena. The social sciences can define laws of behavior. However, with the passage of time it may be discovered that some social scientific laws are only applicable in certain historical contexts.
- Scientific laws describe constant links between an antecedent (cause) and a consequent (effect).

All sciences are developed based on the general scientific laws and the specific laws of each discipline.

Before enunciating a law, it is necessary for a scientist or group of scientists to enunciate a **hypothesis** which is then verified by concrete data. For the hypothesis to become law, it must designate a constant phenomenon and must be testable in different circumstances.

### Examples of scientific laws

**Friction law, first postulate**. The resistance to tangential sliding between two bodies is proportional to the normal force exerted between them.**Friction law, second postulate**. The resistance to tangential sliding between two bodies is independent of the contact dimensions between them.**Newton’s First Law**.**Inertia law**. Isaac Newton was a physicist, inventor, and mathematician. He discovered the laws that govern classical physics. Its first law is: “Every body perseveres in its state of rest or uniform or rectilinear motion, unless it is forced to change its state, by forces impressed on it.”**Second law of Newton**.**Fundamental law of dynamics**.- “The change in motion is directly proportional to the printed motive force and occurs according to the straight line along which that force is printed.”**Newton’s third law. Principle of action and reaction.**“To every action corresponds a reaction”; “With every action an equal and opposite reaction always occurs, that is, the mutual actions of two bodies are always equal and directed in the opposite direction.”**Hubble’s Law**. Physical law. Called the law of cosmic expansion. Postulated by Edwin Powell Hubble, 20th century American astronomer. The redshift of a galaxy is proportional to its distance.**Coulomb law**. Enunciated by Charles-Augustin de Coulomb, French mathematician, physicist and engineer. The law states that, given the interaction of two point charges at rest, the magnitude of each of the electric forces with which they interact is directly proportional to the product of the magnitude of both charges, and inversely proportional to the square of the distance that separates them. . Its direction is that of the lines that connect the loads. If the charges are of the same sign, the force is repulsive. If the charges are of the opposite sign, the forces are repulsive.**Ohm’s law**. Enunciated by Georg Simon Ohm, German physicist and mathematician. It maintains that the potential difference V that arises between the ends of a given conductor is proportional to the intensity of the current I that circulates through said conductor. Between V and I the proportionality factor is R: its electrical resistance. The mathematical expression of Ohm’s Law is represented like this: V = R. I**Law of partial pressures**. Also known as Dalton’s Law, for having been formulated by the British chemist, physicist and mathematician John Dalton. It states that the pressure of a mixture of gases that do not react chemically is equal to the sum of the partial pressures of each of them on the same volume, without varying the temperature.**Kepler’s First Law**.**Elliptical Orbits**. Johannes Kepler was an astronomer and mathematician who discovered invariable phenomena in the motion of the planets. His first law states that all planets move around the sun in elliptical orbits. Every ellipse has two foci. The sun is in one of them.**Kepler’s Second Law. Speed of the planets**. “The radius vector that joins a planet and the sun sweeps equal areas in equal times.”**First Law of Thermodynamics**. Principle of conservation of energy. “Energy is neither created nor destroyed, it only transforms.”**Second law of thermodynamics**. In a state of equilibrium, the values taken by the characteristic parameters of a closed thermodynamic system are such that they maximize the value of a certain magnitude that is a function of said parameters, called entropy.**Third law of thermodynamics**. Nernst’s postulate. It postulates two phenomena: when reaching absolute zero (zero Kelvin) any process in a physical system stops. Upon reaching absolute zero, the entropy reaches a minimum and constant value.**Archimedes’ principle of buoyancy**. Enunciated by the ancient Greek mathematician Archimedes. It is a physical law that states that a body totally or partially submerged in a fluid at rest receives a push from the bottom up that is equal to the weight of the volume of fluid it displaces.**Law of conservation of matter**. Lamonosov Lavoisier’s Law. “The sum of the masses of all the reactants involved in a reaction is equal to the sum of the masses of all the products that are obtained.”**Elasticity law**. Enunciated by Robert Hooke, British physicist. It maintains that, in cases of longitudinal stretching, the unit elongation experienced by an elastic material is directly proportional to the force applied to it.**Heat conduction law**. Postulated by Jean-Baptiste Joseph Fourier, French mathematician and physicist. He maintains that, in an isotropic medium, the heat transfer flux by conduction is proportional and in the opposite direction to the temperature gradient in that direction.